Definitely some translation issues on chapter 11.2. They mention Yukina's mother, but the first chapter clearly shows them finding Yukina in some type of storage pod from the old world. Maybe they were talking about Selka's mother? Or maybe they meant Yukina's friend?
What the heck is that gif from on page 16 of Chapter 21 in the English scanlation?
https://mangadex.org/data/2e882218d95689e981715efb6b08052a/t16.gif
Anyway, I know the translation is a bit of the rails, but isn't the whole series?